#2335 I also opened but I should have noticed we had an issue on JIRA.

If I may add my contribution to this issue (also in "Error in File.stat #2424"):

The issue is preventing me from installing gems on Jruby 1.7.18 (also tested 1.6.8 with same results), as discussed in the forum (https://www.ruby-forum.com/topic/200421 and https://www.ruby-forum.com/topic/6805165#new).

jruby -S jgem install bundler
ERROR: While executing gem ... (Errno::ENOENT)
No such file or directory - C:\Johan_Wasserman.rvm\gems\jruby-1.7.18\gems\bundler-1.7.11

jruby -S irb
irb(main):001:0> File.exists?('/Johan_Wasserman.rvm/test.txt')
=> true
irb(main):002:0> File.expand_path('/Johan_Wasserman.rvm/test.txt')
=> "C:/Johan_Wasserman.rvm/test.txt"
irb(main):003:0> File.absolute_path('/Johan_Wasserman.rvm/test.txt')
=> "C:/Johan_Wasserman.rvm/test.txt"
irb(main):004:0> File.dirname('/Johan_Wasserman.rvm/test.txt')
=> "/Johan_Wasserman.rvm"

My home path in Cygwin is /Johan_Wasserman.rvm, translating to the
Windows canonical path
C:\Zones\Programs\xnix\cygwin64\Johan_Wasserman.rvm

expand_path and absolute_path both returned the windows path
C:\Johan_Wasserman.rvm, which of course is incorrect, and therefore the
gem installer cannot find the files it just downloaded.

rvm info for JRuby and gem env:
jruby-1.7.18:

system:
uname: "CYGWIN_NT-6.1 HP-PC 1.7.33-2(0.280/5/3) 2014-11-13
15:47 x86_64 Cygwin"
system: "cygwin/unknown/x86_64"
bash: "/usr/bin/bash => GNU bash, version 4.1.17(9)-release
(x86_64-unknown-cygwin)"
zsh: " => not installed"

rvm:
version: "rvm 1.26.8 (latest) by Wayne E. Seguin
wayneeseguin@gmail.com, Michal Papis mpapis@gmail.com
[https://rvm.io/]"
updated: "2 hours 47 minutes 50 seconds ago"
path: "/Johan_Wasserman.rvm"

ruby:
interpreter: "jruby"
version: "1.7.18"
" date: "jruby 1.7.18 (1.9.3p551) 2014-12-22 625381c on Java
HotSpot(TM) 64-Bit Server VM 1.8.0_25-b18 +jit [Windows 7-amd64]
platform: "Windows 7-amd64"
patchlevel: "TM"
" full_version: "jruby 1.7.18 (1.9.3p551) 2014-12-22 625381c on Java
HotSpot(TM) 64-Bit Server VM 1.8.0_25-b18 +jit [Windows 7-amd64]

homes:
gem: "/Johan_Wasserman.rvm/gems/jruby-1.7.18"
ruby: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18"

binaries:
ruby: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin/ruby"
irb: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin/irb"
gem: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin/gem"
rake: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin/rake"

environment:
PATH:
"/Johan_Wasserman.rvm/gems/jruby-1.7.18/bin:/Johan_Wasserman.rvm/gems/jruby-1.7.18@global/bin:/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin:/Johan_Wasserman.rvm
/Program Files (x86)/Java/jre1.8.0_25/bin/client:/cygdrive/c/Program
Files (x86)/Java/jre1.8.0_25/bin:/cygdrive/c/Program Files
(x86)/Java/jre1.8.0_25/lib/i386:/cygdrive/c/Progr
Zones/Programs/Java/jre1.8.0_20/bin:/cygdrive/c/Windows/system32:/cygdrive/c/Windows:/cygdrive/c/Windows/System32/Wbem:/cygdrive/c/Windows/System32/WindowsPowerShell/v1.0:/cygdr
gdrive/c/Users/Johan Wasserman/AppData/Roaming/npm:/cygdrive/c/Program
Files/Boot2Docker for Windows:/cygdrive/c/Zones/Develoment/Aptana Studio
3 Workspace:/usr/lib/lapack"
GEM_HOME: "/Johan_Wasserman.rvm/gems/jruby-1.7.18"
GEM_PATH:
"/Johan_Wasserman.rvm/gems/jruby-1.7.18:/Johan_Wasserman.rvm/gems/jruby-1.7.18@global"
MY_RUBY_HOME: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18"
IRBRC: "/Johan_Wasserman.rvm/rubies/jruby-1.7.18/.irbrc"
RUBYOPT: ""
gemset: ""

RubyGems Environment:

• RUBYGEMS VERSION: 2.1.9
• RUBY VERSION: 1.9.3 (2014-12-22 patchlevel 551) [java]
• INSTALLATION DIRECTORY: /Johan_Wasserman.rvm/gems/jruby-1.7.18
• RUBY EXECUTABLE:
  C:/Zones/Programs/xnix/cygwin64/Johan_Wasserman.rvm/rubies/jruby-1.7.18/bin/jruby.exe
• EXECUTABLE DIRECTORY: /Johan_Wasserman.rvm/gems/jruby-1.7.18/bin
• SPEC CACHE DIRECTORY: C:/Zones/Programs/xnix/cygwin64/home/Johan
  Wasserman/.gem/specs
• RUBYGEMS PLATFORMS:
  • ruby
  • universal-java-1.8
• GEM PATHS:

  • /Johan_Wasserman.rvm/gems/jruby-1.7.18

    /Johan_Wasserman.rvm/gems/jruby-1.7.18:/Johan_Wasserman.rvm/gems/jruby-1.7.18@global
• GEM CONFIGURATION:
  • :update_sources => true
  • :verbose => true
  • :backtrace => false
  • :bulk_threshold => 1000
  • "install" => "--no-rdoc --no-ri --env-shebang"
  • "update" => "--no-rdoc --no-ri --env-shebang"
• REMOTE SOURCES:
  • https://rubygems.org/

• SHELL PATH:

  C:\Zones\Programs\xnix\cygwin64\Johan_Wasserman.rvm\gems\jruby-1.7.18\bin

  C:\Zones\Programs\xnix\cygwin64\Johan_Wasserman.rvm\rubies\jruby-1.7.18\lib\ruby\gems\shared\bin

  C:\Zones\Programs\xnix\cygwin64\Johan_Wasserman.rvm\rubies\jruby-1.7.18\bin
  • C:\Zones\Programs\xnix\cygwin64\Johan_Wasserman.rvm\bin
  • C:\Zones\Programs\xnix\cygwin64\usr\local\bin
  • C:\Zones\Programs\xnix\cygwin64\bin
  • C:\Program Files (x86)\Java\jre1.8.0_25\bin\client
  • C:\Program Files (x86)\Java\jre1.8.0_25\bin
  • C:\Program Files (x86)\Java\jre1.8.0_25\lib\i386
  • C:\ProgramData\Oracle\Java\javapath
  • C:\Zones\Programs\Java\jre1.8.0_20\bin
  • C:\Windows\system32
  • C:\Windows
  • C:\Windows\System32\Wbem
  • C:\Windows\System32\WindowsPowerShell\v1.0
  • C:\Zones\Programs\nodejs
  • C:\Zones\Programs\xnix\cygwin64\bin
  • C:\Users\Johan Wasserman\AppData\Roaming\npm
  • C:\Program Files\Boot2Docker for Windows
  • C:\Zones\Develoment\Aptana Studio 3 Workspace
  • C:\Zones\Programs\xnix\cygwin64\lib\lapack

This issue specifically fixes the problem reported in the original Jira issue. Namely, that IO/File.open of a unix-style absolute path will end up using the current directory drive letter like MRI does.

For @johanwasserman if this does not help then you can open up a new issue. Strangely enough, MRI's windows release behaves exactly as JRuby for the methods you mention above expand_path, absolute_path, dirname. This was quite surprising to me :)